Alzheimer's disease (usually abbreviated as AD) is the most common dementia among the elderly. Its histopathological manifestations are mainly senile plaques, neurofibrillary entanglement, and the death of regional neurons caused by apoptosis and so on.
Studies have shown that abnormal deposition of amyloid β-protein (usually abbreviated as Aβ) is one of the main pathogenesis of Alzheimer's disease. Amyloid β-protein is a polypeptide containing 39 to 43 amino acids produced by proteolytic action of amyloid precursor protein (APP) by β and γ secretase. Commonly in the human body is a peptide containing 40 (Aβ1˜40) or 42 (Aβ1˜42) amino acids, wherein Aβ1˜42 has a stronger toxicity, easier to accumulate into the core of amyloid β-protein deposition plaque, and the amyloid β-protein deposition plaque formed the deposition of amyloid β-protein can cause neurotoxicity. In normal physiological conditions, amyloid β-protein can be detected in both blood and cerebrospinal fluid, suggesting that amyloid β-protein itself does not cause Alzheimer's disease, whereas the deposition of amyloid β-protein is one of the causes of Alzheimer's disease.
Studies have shown that a large number of amyloid β-protein deposition plaques have accumulated in the hippocampus and cortical regions of the brain of patients with Alzheimer's disease, and reducing the amount of amyloid β-protein in the brain can delay or relieve the symptoms of Alzheimer's disease.
Amyloid β-protein can be degraded by a variety of peptidases, such as insulin-degrading enzymes (IDE) and neutral endopeptidase (NEP), both of which are zinc-dependent endoproteases. Studies have shown that in the presence of IDE and NEP, amyloid β-protein will be significantly reduced, but in the absence of IDE and NEP, how to destroy the structure of amyloid β-protein and reduce the accumulation of amyloid β-protein become one of the means to study the pathogenesis of Alzheimer's disease and even the treatment of Alzheimer's disease, and there is currently no way to effectively destroy the structure of amyloid β-protein.